Interactive Finite Element Analysis of Highway Bridges

Abstract

Despite the well established benefits of using finite element methods, commercially available finite element packages have not received wide-spread application to the analysis of highway bridges. This is because they do not have the special features needed by bridge engineers.<P>In particular, the lack of pre- and post-processors suited for the finite element analysis of the bridges is one of the major reasons why the running of finite element program, as a standard part of bridge design, has always been a time consuming process. Currently available bridge software provides few facilities to easily set up, edit, and query information about the design problem description, and the response output to various truck loading conditions. Often the designer is given a textual echo of the input, but no graphical verification that a problem has been well formed. This problem is particularly acute when the design problem definition, and ensuing finite element analysis, needs to be repeated several times.<P>Furthermore, general purpose finite element packages often do not provide for automatic generation of moving truck and lane loads for the maximum effect.<P>The purpose of this study is development of an interactive graphically based pre-processor for the finite element analysis of highway bridges with high-speed engineering workstations. The pre-processor gives engineers the choice of using both keyboard and mouse styles of interaction to describe and edit bridge geometries, set boundary conditions, and place trucks at the desired positions on the bridge. For our program, entitled XBUILD, the finite element software along with the pre-processor and post-processor, execute on separate workstations. They communicate via message passing and socket- based Interprocess Communication.